In a broadband communications system, when receiving data, a receiver usually performs frequency-domain equalization, so as to resist channel frequency-domain selective fading caused by multiple paths. When the receiver performs frequency-domain equalization, it needs to be ensured that no inter-symbol interference is caused by a received symbol over a next symbol, and therefore, it is required to reserve a guard period before each symbol to resist inter-symbol interference from a previous symbol. Frequently-used guard period design methods include a cyclic prefix (CP) method, a zero prefix (ZP), and a zero tail (ZT) method. In addition, to reduce power consumption of a base station and user equipment (UE), currently coverage of the base station may be expanded by using multiple antennas to perform beamforming (BF), including digital beamforming (DBF), analog beamforming (ABF), and hybrid beamforming (HBF). Beamforming in the ABF technology and the HBF technology is completed by relying on a radio-frequency phase shifter. When adjusting a phase, the radio-frequency phase shifter needs to take time, that is, an impact of beam switching time needs to be considered.
Currently, in actual application, for example, in a CP communications system, as shown in FIG. 1, considering the beam switching time, a guard period (GP) is reserved before a CP of a symbol at which beam switching needs to be performed, so that beam switching does not affect normal sending or receiving of a next symbol. However, in this manner, an extra GP needs to be reserved based on the CP, thereby reducing available air interface resources, causing air interface resource utilization to decrease, and reducing a system capacity.